Noisy 6.4L

Hi,

I've had my Scat Pack since July. Its 6.4 has been a noisy engine since day one. Lots of ticking. I have grown used to it, and don't sweat it too much. But today I noticed a slightly different sound. I was sitting at a stop light with no music on, and the ticking seemed louder than normal. However, when I would depress the clutch pedal, the loud ticking would stop, and only the "normal" quiet ticking remained. When I let the pedal out again, the loud ticking would return.

Any ideas? Is this something common or normal that I simply haven't noticed till now?

Thanks.